Yes, they are very common in countries where the short term profits are king. The problem with aerial spraying is wind: you don't want your herbicides/insecticides to be sprayed out of your field: as it can kill bees or local population of butterflies and other insects as well as local herbs and plants that grow around.
In EU we banned the aerial spraying (in most cases) as well as have quite complex rules to minimise this pollution: like not using spray in form of aerosols and such.